Steven J. Murdoch presents some interesting results indicating that the EURion constellation may have been obsoleted:

Recent printers, scanners and image manipulation software identify images of currency, will not process the image and display an error message linking to www.rulesforuse.org. The detection algorithm is not disclosed, however it is possible to test sample images as to whether they are identified as currency. This webpage shows an initial analysis of the algorithm's properties, based on results from the automated generation and testing of images. [...]

Initially it was thought that the "Eurion constellation" was used to identify banknotes in the newly deployed software based system, since this has been confirmed to be the technique used by colour photocopiers, and was both necessary and sufficient to prevent an item being duplicated using the photocopier tested. However further investigation showed that the detection performed by software is different from the system used in colour photocopiers, and the Eurion constellation is neither necessary nor sufficent, and in fact it probably is not even a factor.